External rotor drive

ABSTRACT

A rotary body for a printing press, comprising a stator and a rotor, which can be rotated in relation to the stator and equipped with at least one permanent magnet. At least one stator winding is provided in the stator in such a way that a torque, which acts on the rotor, can be generated by the interaction of said winding with the at least one permanent magnet of the rotor. A drive for a printing press, comprising a rotary body of this type, is also provided.

This application is the U.S. national phase application of PCTInternational Application No. PCT/EP2004/013784, filed Dec. 3, 2004, andclaims priority to German Patent Application No. 103 58 293.2, filed onDec. 12, 2003.

FIELD OF THE INVENTION

The present invention relates to a rotary-driven rotation body for aprinting machine and to a printing machine drive which uses such arotation body.

BACKGROUND OF THE INVENTION

Transfer cylinders of a printing machine, such as for example printingcylinders, are commonly driven by a motor which is for example connectedto the transfer cylinder via a gearing mechanism.

A transfer cylinder is known from DE 195 30 283 A1, comprising anintegrated external rotor motor, wherein the rotor is formed by a hollowpart of the transfer cylinder, on the inner side of which magnets aremounted.

SUMMARY OF THE INVENTION

It is an object of the invention to suggest a rotary-driven rotationbody and a printing machine drive which are suitable for driving one ormore of any rotation bodies or cylinders of a printing machine with asufficiently large torque.

A rotation body in accordance with the invention comprises anelectromotive external rotor drive, wherein a shell or cylinder elementis designed as a rotor and is for example hollow on the inside orcomprises a blind hole and, in at least a partial area and preferablyapproximately over the whole area of the longitudinal axis, comprisesone or more magnetic elements on its inner side, in particular permanentmagnets which can for example consist of a rare earth metal and generatea magnetic field in the interior of the rotation body or cylinder, inorder for example to serve as a permanent activator for analternating-current motor or rotary-current motor. The cylinder or rotorconnected to the permanent magnet is pivoted on or relative to a statorwhich is located in at least a partial area of the cylinder or rotor,preferably in its interior, and preferably extends along approximatelythe entire longitudinal axis of the cylinder. Thus, in accordance withone embodiment, the stator can be provided in a blind hole of thecylinder or can also extend through the entire cylinder, wherein in thiscase, the cylinder only consists for example of a shell connected topermanent magnets. At least one conduit or magnetic coil is arranged inthe stator such that, when a current flows through the conduit ormagnetic coil, a torque acts on the rotor or cylinder pivoted relativeto the stator and can for example drive, accelerate or also deceleratethe cylinder.

In principle, the invention can be used in individual rotation bodies orall the rotation bodies of a printing machine which are to be driven,such as for example in one or more central cylinders or steel cylinders,printing blanket cylinders, form cylinders or plate cylinders, rubbercylinders, knife cylinders, collecting cylinders and/or cuttingcylinders, inking rollers and/or dampening rollers and/or in the foldingapparatus. In particular, for example once the rotation body surface hasbeen correspondingly coated or machined, the rotation body itself canfor example form one of the cited cylinders or rollers of the printingmachine or can serve as a bearing or support for the same, wherein forexample a cylindrical roller body is slid onto and for example fixed onthe rotation body.

The stator preferably comprises at least one electrical conduit, inparticular one or more magnetic coils or windings which are arrangedsuch that, when a current flows through the conduits or windings, atorque is generated on the rotor connected to permanent magnets.External rotor motors and the arrangement of stator windings are knownin the prior art. Reference is made for example to DE 102 13 743 A1, thetechnical teaching of which with respect to the construction of anexternal rotor motor is incorporated into this application. Inaccordance with the invention, one or more stator windings can beprovided along the axial direction of the stator, such that over apartial area, for example half the length of the rotor, or over a largerarea, preferably over the entire length of the rotor, a magnetic fieldfor driving the rotor can be generated, wherein the stator windings canbe provided as windings on the outer surface of the stator, such thatthey act as electromagnets which co-operate for example with permanentmagnets in or on an inner surface of the rotor or rotor casing, in orderto be able to generate an accelerating or decelerating force whichinfluences the rotation of the rotor.

As described above, the rotor or cylinder can be pivoted or mounted onthe stator either directly or for example via one or more ball bearings.

It is also possible for the rotor to not be directly mounted to thestator, but to be attached to an external wall or housing, for exampleto the side wall of a printing machine, such that it is pivoted. Therotor can also for example be connected on one side to the stator via aball bearing and on an opposing side to an external retainer, such asfor example a side wall of a printing machine, via a ball bearing.

It is also possible for the stator to be connected in a non-positiveand/or positive lock to a retainer, such as for example a printing framewall. In accordance with the invention, a prefabricated roller motor, inparticular an external rotor motor, can thus be used to drive printingmachine rollers and/or cylinders, wherein the motor can for example becompletely prefabricated, i.e. can comprise the rotor and the stator,wherein the rotor casing comprises permanent magnets on its innersurface and the stator comprises windings as electromagnets on its outersurface. The rotor casing can exhibit an outer diameter or a profilewhich for example corresponds to the recess or the inner diameter orprofile in a printing cylinder or in a roller, wherein in order toachieve a good frictional lock between the rotor casing and the printingcylinder or roller, the interlocking surfaces can preferably be designedslightly conical. The external rotor outer surface can for example bedesigned conical.

Advantageously, the length of the stator measures such that it does notextend beyond the partition wall measurement of the bearing locations orbearing walls which are reciprocally distanced in parallel, inparticular the printing frame walls.

Printing unit cylinders and/or rollers can thus be simply fitted with ordismantled from a pre-fitted external rotor motor between printing unitwalls distanced in parallel. Various printing format sections can alsobe combined into one motor output range, for example by designing therotor casing diameter with different measurements.

In accordance with the invention, the rotation body consisting of thestator and the rotor can be designed as a magnetically sealed system andcan thus have little external magnetic effect, such that magneticeffects on neighbouring metallic objects are prevented, wherein the wallthickness on a printing unit cylinder or printing unit roller can forexample be selected such that the rotation body or the motor ismagnetically sealed.

A cooling unit is preferably provided on the stator and particularlypreferably connected to the stator or in the stator. A cooling medium,such as for example a cooling fluid, in particular cooling water, canfor example be channelled through a partial area or also through theentire stator, i.e. for example over the entire length of the stator, inorder for example to be able to channel away waste heat arising in thestator from the stator windings. Other cooling elements or coolingmechanisms can likewise be used, such as for example cooling an outer orperipheral area of the stator, which can also sufficiently cool areas orcomponents of the stator if the stator is made from a heat-conductivematerial, such as for example iron.

Heated components, such as for example a stator winding, canadditionally or alternatively be cooled by a current of air channelledover them. A current of air can also advantageously be generated byrotating the cylinder or rotor, wherein elements or flywheels are forexample attached on the inner side of the rotor and can generate acurrent of air approximately in the axial direction when the rotor isrotated.

Attaching conduits for current and/or a cooling medium in the stator isrelatively simple, since the stator does not move relative to itsattachment location and thus sliding contacts or the like can forexample be omitted.

The electrical conduits or magnetic coils, used as stator windings,and/or a cooling system, i.e. for example conduits for a cooling medium,particularly preferably extend approximately over the entire length ofthe stator, wherein a number of stator windings can for example beprovided, distributed from a first end up to a second end of the stator,axially distanced. This enables the rotor or cylinder to be driven overthe entire length of the rotor or stator, which are advantageously ofapproximately equal length, such that a larger torque and/or drivingforce can be generated as compared to a drive which is only provided ina partial area of the rotor.

The magnetic element or elements connected to the rotor are preferablyprovided in the area of or on the inner side of the rotor and can forexample be designed annular, wherein a number of magnetic rings can forexample be provided on the inner side along the axial direction of thecylinder, each exhibiting a predefined distance from each other. It islikewise also possible for individual separate magnets to be provided onthe inner side of the rotor, which are constructed such that a magneticfield necessary to actuate an external rotor motor is generated. It isalso possible for the magnets to be designed as rods or for acombination of individual magnets, annular magnets or rod magnets.

The rotation body in accordance with the invention can for example beused in conjunction with or also as a rubber blanket cylinder, a platecylinder, a deflecting cylinder, a drawing roller, a ductor or a reelchanger.

The invention relates not only to the combination of a rotor asdescribed above with a stator as described above, but also to such arotor or such a stator in its own right, not in conjunction with theother element in each case.

The invention thus enables rollers to be made comprising idle shaftjournals, significantly simplifying assembling and disassemblingrollers. The drive of such a roller is likewise advantageous, since theroller shell can have a smaller mass and thus a smaller inertial massrelative to a roller which is designed solid.

In accordance with another aspect, the invention relates to a printingmachine drive which uses such a rotation body.

In such a printing machine drive, a control device is preferablyprovided for controlling the current flowing in conduits or windings ofthe rotor. The control device can for example control the frequency, thevoltage and/or the strength of the current, in order for example to thusregulate the speed of the rotor and to accelerate, synchronise ordecelerate the rotor in accordance with predefined printing states orprinting conditions.

A sensor can preferably be provided which detects an angular position ofthe rotor, in order for example to form a regulating circuit inconjunction with a control device as described above, wherein forcontrolling the synchronisation of a number of printing cylinders withrespect to each other, individual angular positions of various rotorsare also detected and the control of the stator windings is controlledor regulated in accordance with the detected angular positions and, asapplicable, in accordance with predefined target values, such that forexample a frequency, voltage and/or strength of the current is appliedto the stator windings in order to stop or restart the synchronisationof a number of printing cylinders.

The rotation body rotary-driven in accordance with the invention isparticularly preferably used as a driving motor of a cylinder groupingconsisting of a mechanically coupled plate cylinder and a rubber blanketcylinder. In particular, the rotation body in accordance with theinvention is used as a rubber blanket cylinder or as a plate cylinder insuch a paired drive, wherein at least one rotation body in accordancewith the invention is provided in such a cylinder grouping, and a numberof cylinder groupings are preferably driven by a number of such rotationbodies. Reference is made to EP 0 644 048 belonging to the applicant,the technical teaching of which with respect to forming cylindergroupings in pairs using a rubber blanket cylinder and a plate cylinderof a rotation machine and jointly driving such a cylinder grouping usinga separate driving motor per cylinder grouping, and with respect to theuse of toothed belts and the general construction of printing machinedrives, is incorporated into this application. Using a rotary-drivenrotation body in accordance with the invention, a separate motor fordriving a rubber blanket cylinder or a plate cylinder coupled to it canthus be omitted in the arrangement described in EP 0 644 048, since therubber blanket cylinder or the plate cylinder themselves are designed asa rotary-driven rotation body in accordance with the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a rotation body comprising twovariants of an external rotor drive;

FIG. 2 is a cross-sectional view of an example embodiment of an axiallymovable external rotor motor;

FIG. 3 is a cross-sectional view of an embodiment of an axiallyimmovable external rotor motor; and

FIGS. 4 a and 4 b are schematic diagrams of rollers or cylinders whichare driven by one or two rotation bodies in accordance with theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a rotation body 15 including a stator 1 of a roller body orplate cylinder 9, in each case laterally fixed and not pivoted in aretainer 10. The retainer 10 can for example be the outer wall of aprinting machine. Stator windings 3 a, 3 b and a circuit 4 for a coolingmedium are provided in the interior of the stator 1 in order to be ableto channel away waste heat arising in the stator 1, for example from aflow of current through the stator windings 3 a, 3 b. The statorwindings 3 a, 3 b are connected via a three-phase motor cable to afrequency control unit 5 which is provided outside the stator 1 andpreferably outside the printing machine, for example on the outer wall10 of the printing machine.

On the circumferential side of the stator 1, a ball bearing 6 a which ispreferably axially movable is provided on each end of the stator 1, therotor 2 being supported on said ball bearing 6 a such that the rotor 2can rotate relative to the stator 1. In the two embodiments shown,permanent magnets 7 a, 7 b are attached to the inner side of the rotor 2and generate a magnetic field necessary for an external rotor motor. Inthe embodiment shown, the rotor 2 is used as a plate cylinder, with aroller body 9 which is placed or slid onto the rotor and held in anon-positive, frictional or positive lock by a conical or truncatedconical area 2 a of the rotor 2.

Alongside the plate cylinder shown by way of example in FIG. 1, a rubberblanket cylinder can be arranged which is either mechanically coupled tothe plate cylinder and thus driven by it, or which can likewise bedesigned as a rotary-driven rotation body comprising the elements 1 to 7of the plate cylinder as described above, with a rubber blanket cylinder9 placed on it.

An angle measuring device or transmitter 8 measures the current positionor rotary position and/or rotary angle of the rotor 2 and therefore ofthe roller body 9 connected fixedly to the rotor 2 and can output thedetected rotary position signals to the frequency control unit 5 whichcan output control signals or currents to the stator windings 3 a, 3 b,for example together with transmitters and/or control units of otherrotation bodies or rollers, such that a number of rollers can besynchronised.

FIG. 2 shows an alternative embodiment of the rotation body 15′including an axially movable external rotor motor, on which a rollerbody 9 as shown in FIG. 1 is placed. The bearings 6 a for pivoting therotor 2 on the stator 1 are movable in the axial direction of the stator1 or connected to the stator 1 and enable the rotor 2 to move axiallyrelative to the stator 1, wherein the permanent magnets 7 a attached tothe inner side of the rotor 2 extend further in the axial directionand/or are provided over a greater length than the length of the statorwinding 3 a in the axial direction, enabling a substantially identicalmagnetic field to be generated by the permanent magnets 7 a connected tothe rotor 2, even when the rotor 2 is moved axially relative to thestator 1 within a predefined range, in order to exert a driving ordecelerating force on the rotor 2 in conjunction with theelectromagnetic field generated by the stator windings 3 a when acurrent flows through them.

FIG. 3 shows another embodiment of a rotation body 15″ in accordancewith the invention, comprising ball bearings 6 b which do not enable therotor 2 to move axially relative to the stator 1. The radial extentand/or length of the permanent magnets 7 b in the radial direction canthus approximately correspond to the length of the stator winding 3 b inthe radial direction, without leading to a significant change in themagnetic coupling between the permanent magnets 7 b and the statorwinding 3 b, necessary for generating a rotation or rotary force, duringthe operation of the external rotor motor.

FIG. 4 a shows an embodiment of a roller driven by an external rotormotor or a driven cylinder 9, wherein on only one side of the roller orcylinder 9—the left-hand side in FIG. 4 a—a rotation body 15 with anexternal rotor motor as described above is introduced, for example onlylaterally, into the roller or the cylinder 9, and the roller or cylinder9 is supported at the opposing end by a conventional shaft journal 11.The motor schematically shown in FIG. 4 a can for example be introducedinto the roller or the cylinder only laterally, or can extend acrosslarger areas of the axial length of the roller or cylinder 9, such asfor example up to half the axial length, beyond half the axial length oreven over the entire axial length of the roller or cylinder 9.

FIG. 4 b shows another embodiment, wherein contrary to the example shownin FIG. 4 a, a rotation body 15 with an external rotor motor asdescribed above is provided at both ends of the roller or cylinder 9.

The motor shown in FIGS. 4 a and 4 b can generally be any of the motorsdescribed with reference to FIGS. 1 to 3.

1-16. (canceled)
 17. A rotation body for a printing machine, comprising:a stator including at least one stator winding; and a rotor including atleast one permanent magnet and positioned for rotation relative to thestator wherein current flowing through the stator winding interacts withthe at least one permanent magnet and generates a torque acting on therotor.
 18. The rotation body according to claim 17, wherein at least twostator windings are provided at axially offset points on the stator. 19.The rotation body according to claim 17, wherein the at least one statorwinding generates a magnetic field for driving the rotor over at leasthalf of an axial length of the rotor.
 20. The rotation body according toclaim 17, wherein the at least one stator winding is distributed overapproximately an entire axial length of the stator.
 21. The rotationbody according to claim 17, wherein the at least one stator winding isprovided on an outer surface of the stator.
 22. The rotation bodyaccording to claim 17, wherein the rotor is a cylinder shell.
 23. Therotation body according to claim 17, wherein the rotor is a cylinderbody comprising a blind hole.
 24. The rotation body according to claim17, wherein the rotor is mounted on the stator by at least one bearingextending between the rotor and the stator, at least one bearingextending between the rotor and an external retainer, or at least afirst bearing extending between the rotor and the stator and at least asecond bearing extending between the rotor and the external retainer.25. The rotation body according to claim 17, further comprising acylinder body or roller body which is supported on the rotor and fixedthereto by a non-positive frictional lock, a positive lock or by acombination of a non-positive frictional lock and a positive lock. 26.The rotation body according to claim 17, further comprising a coolingsystem for cooling at least a partial area of the stator.
 27. Therotation body according to claim 17, wherein the at least one permanentmagnet is annular, rod-shaped or a combination of annular and-rodshaped.
 28. The rotation body according to claim 17, wherein the atleast one permanent magnet is provided on a rotor casing inner surface.29. The rotation body according to claim 17, wherein the rotor supportsor defines a deflecting cylinder, a drawing roller, a ductor, a centralcylinder, a steel cylinder, a printing blanket cylinder, a formcylinder, a plate cylinder, a rubber cylinder, a knife cylinder, acollecting cylinder, a cutting cylinder, an inking roller, or dampeningroller.
 30. The rotation body according to claim 17, wherein the rotoris used in a folding apparatus or in a reel changer.
 31. A printingmachine drive comprising a rotation body according to claim
 17. 32. Theprinting machine drive according to claim 31, further comprising acontrol device configured to one or more of a voltage, a strength of acurrent and a frequency of a current flowing in the at least one statorwinding.
 33. The printing machine drive according to claim 31, furthercomprising an angle sensor for measuring a rotary position of the rotor.34. A rotation printing machine comprising rubber blanket cylinders andcounter printing cylinders that together form printing points, andfurther comprising plate cylinders which are mechanically coupled inpairs with the rubber blanket cylinders into cylinder groupings, whereineach cylinder grouping is driven by one or more of the plate cylinder,rubber blanket cylinder or the counter printing cylinder including arotation body according to claim
 17. 35. The rotation body according toclaim 17 wherein the rotation body defines a bearing for a cylinder or aroller of a printing machine.
 36. A method of driving a cylinder orroller of a printing machine, the method comprising: providing at leastone rotation body comprising: a stator supported by the printing machineand including at least one stator winding; and a rotor including atleast one permanent magnet and positioned for rotation relative to thestator; positioning the cylinder or roller about the rotor; andselectively providing current through the stator winding.